Problem: Khan.scratchpad.disable(); For every level Kevin completes in his favorite game, he earns $450$ points. Kevin already has $360$ points in the game and wants to end up with at least $3510$ points before he goes to bed. What is the minimum number of complete levels that Kevin needs to complete to reach his goal?
Solution: To solve this, let's set up an expression to show how many points Kevin will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Kevin wants to have at least $3510$ points before going to bed, we can set up an inequality. Number of points $\geq 3510$ Levels completed $\times$ Points per level $+$ Starting points $\geq 3510$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 450 + 360 \geq 3510$ $ x \cdot 450 \geq 3510 - 360 $ $ x \cdot 450 \geq 3150 $ $x \geq \dfrac{3150}{450} = 7$ Kevin must complete at least 7 levels.